Definition

A fusion protein composed of the extracellular domain of human tumor necrosis factor receptor superfamily member 13B (TNFRSF13B; transmembrane activator and calcium modulator and cyclophilin ligand interactor; TACI) fused to a human immunoglobulin (Ig) fragment crystallizable (Fc) domain, with potential immunomodulating activity. Upon administration, telitacicept targets both tumor necrosis factor ligand superfamily member 13B (TNFSF13B; BAFF; B lymphocyte stimulator; BLyS) and tumor necrosis factor ligand superfamily member 13 (TNFSF13; a proliferation-inducing ligand; APRIL) and inhibits their interaction with their cell membrane receptors, including TACI, tumor necrosis factor receptor superfamily member 17 (TNFRSF17; B-cell maturation antigen; BCMA) and tumor necrosis factor receptor superfamily member 13C (TNFRSF13C; BAFF receptor; BAFF-R). This inhibits B-cell proliferation and maturation, thereby inhibiting B-cell mediated autoimmune responses. APRIL and BAFF, and their interactions with their receptors TACI, BCMA and BAFF-R, play important roles in in B-cell proliferation and survival.